This invention relates to apparatus for tightening a joint assembly including a fastener assembly to its yield point and, more particularly, to operator powered apparatus or similar apparatus wherein the tightening force is applied incrementally.
Recent advances in the art have provided generally satisfactory methods and apparatus for determining when joints including fastener assemblies have been tightened to the yield point. For example, U.S. Pat. No. 3,982,419 discloses such a method and apparatus, and U.S. Pat. Nos. 3,973,434 and 4,000,782 also disclose such a method and apparatus including checking means for determining certain easily measurable tightening characteristics of the fastener assembly after it has been tightened to the yield point. In view of these advances, tightening to the yield point is becoming more widely used in the manufacture of original equipment.